# What is the Sum of First 120 Natural Numbers? getcalc.com's Arithmetic Progression (AP) calculator, formula & workout to find what is the sum of first 120 natural numbers.
7260 is a sum of number series from 1 to 120 by applying the values of input parameters in the formula.

## How to Find Sum of First 120 Natural Numbers?

The below workout with step by step calculation shows how to find what is the sum of natural numbers or positive integers from 1 to 120 by applying arithmetic progression. It's one of an easiest methods to quickly find the sum of any given number series.
step 1 address the formula, input parameters & values.
Input parameters & values:
The number series 1, 2, 3, 4, . . . . , 119, 120.
The first term a = 1
The common difference d = 1
Total number of terms n = 120

step 2 apply the input parameter values in the formula
Sum = n/2 x (a + Tn)
= 120/2 x (1 + 120)
= 14520/2
1 + 2 + 3 + 4 + . . . . + 119 + 120 = 7260

Therefore, 7260 is the sum of positive integers upto 120. 